{"sport":"mlb","slug":"john-atz","bio":{"fullName":"John Atz","position":"2B","team":"CWS","heightInches":69,"weightLbs":150,"birthDate":"1879-07-01","rookieSeason":1902,"lastSeason":1909,"status":"RET","externalIds":{"mlbam":"110372","chadwick":"b167c2a1","retro":"atz-j101","wikidata":"Q2136440"}},"draft":null,"statTables":[{"id":"batting","label":"Batting","columns":[{"key":"g"},{"key":"ab"},{"key":"r"},{"key":"h"},{"key":"doubles"},{"key":"triples"},{"key":"hr"},{"key":"rbi"},{"key":"sb"},{"key":"bb"},{"key":"so"},{"key":"avg"},{"key":"obp"},{"key":"slg"},{"key":"ops"}],"rows":[{"season":1902,"seasonType":"REG","team":"MIN","gamesPlayed":3,"values":{"g":3,"ab":10,"r":1,"h":1,"doubles":0,"triples":0,"hr":0,"rbi":0,"sb":0,"bb":0,"so":null,"avg":0.1,"obp":0.1,"slg":0.1,"ops":0.2},"rowScope":"team"},{"season":1907,"seasonType":"REG","team":"CWS","gamesPlayed":4,"values":{"g":4,"ab":8,"r":0,"h":1,"doubles":0,"triples":0,"hr":0,"rbi":0,"sb":0,"bb":0,"so":null,"avg":0.125,"obp":0.125,"slg":0.125,"ops":0.25},"rowScope":"team"},{"season":1908,"seasonType":"REG","team":"CWS","gamesPlayed":85,"values":{"g":85,"ab":206,"r":24,"h":40,"doubles":3,"triples":0,"hr":0,"rbi":27,"sb":9,"bb":31,"so":null,"avg":0.194,"obp":0.311,"slg":0.209,"ops":0.52},"rowScope":"team"},{"season":1909,"seasonType":"REG","team":"CWS","gamesPlayed":119,"values":{"g":119,"ab":381,"r":39,"h":90,"doubles":18,"triples":3,"hr":0,"rbi":22,"sb":14,"bb":38,"so":null,"avg":0.236,"obp":0.309,"slg":0.299,"ops":0.608},"rowScope":"team"}],"careerTotals":{"REG":{"g":211,"ab":605,"r":64,"h":132,"doubles":21,"triples":3,"hr":0,"rbi":49,"sb":23,"bb":69,"so":null,"avg":0.218,"obp":0.304,"slg":0.263,"ops":0.567}}},{"id":"advanced","label":"Advanced (League-Relative)","columns":[{"key":"ops_plus","label":"OPS+","description":"On-base plus slugging vs the player's own season+league (100 = league average). Park-unadjusted; OBP uses a consistent (H+BB)/(AB+BB) rate. Higher is better.","format":"int","higherIsBetter":true},{"key":"era_plus","label":"ERA+","description":"Earned-run average vs the player's own season+league (100 = league average). Park-unadjusted. Higher is better.","format":"int","higherIsBetter":true}],"rows":[{"season":1902,"seasonType":"REG","team":"MIN","values":{"ops_plus":-42,"era_plus":null},"rowScope":"team"},{"season":1907,"seasonType":"REG","team":"CWS","values":{"ops_plus":-17,"era_plus":null},"rowScope":"team"},{"season":1908,"seasonType":"REG","team":"CWS","values":{"ops_plus":73,"era_plus":null},"rowScope":"team"},{"season":1909,"seasonType":"REG","team":"CWS","values":{"ops_plus":100,"era_plus":null},"rowScope":"team"}],"careerTotals":{"REG":{"ops_plus":87,"era_plus":null}},"advancedMeta":{"method":"computed in-house from MLB StatsAPI season batting/pitching lines, normalized to each player's own (season, league) baseline","formulas":{"era_plus":"100 * lgERA / playerERA (league ERA = 9 * ΣER / ΣIP over the season+league)","ops_plus":"100 * (OBP/lgOBP + SLG/lgSLG - 1)","career_era_plus":"innings-weighted league ERA / career ERA (B-Ref method)","career_ops_plus":"AB-weighted OBP & SLG against AB-weighted league rates"},"caveats":["PARK-UNADJUSTED: no park-factor data exists in the corpus, so these are league-relative but not park-adjusted (true B-Ref ERA+/OPS+ also divide by a park factor)","OBP baseline uses a consistent (H+BB)/(AB+BB) reached-base rate for BOTH player and league — the source feed carries no HBP or SF, so this is not the full (H+BB+HBP)/(AB+BB+HBP+SF) OBP; SLG is exact from the hit-type columns","league resolved from team code + season (most-recently-founded franchise existing by that season); the same resolver builds the baseline and looks up the player, so ratios stay internally coherent","a (season, league) bucket below the sample floor (3000 AB batting / 1000 IP pitching) yields null — no noisy baselines","regular season only; postseason lines are excluded from league baselines and metrics","AL and NL and each historical/Negro league are normalized separately — never blended across leagues or eras"]}}],"dataSources":["MLB StatsAPI (statsapi.mlb.com — official public league API; facts only, raw payloads not republished)"],"generatedAt":"2026-07-03T07:50:50.720Z"}